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991.
N. R. Sadykov 《Theoretical and Mathematical Physics》2006,149(1):1354-1365
In the geometric optics approximation, we comparatively analyze the polarization effects resulting from the influence of polarization
on the beam trajectory. We show that the beam trajectory equations describing the optical Magnus effect that are obtained
from the canonical Hamilton equations, Fermat principle, and truncated vector wave equations give the same result, coincident
with the result in the mode approach. We explain the reasons underlying the previously derived results.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 149, No. 1, pp. 65–79, October, 2006. 相似文献
992.
An almost contact metric structure is parametrized by a section σ of an associated homogeneous fibre bundle, and conditions
for σ to be a harmonic section, and a harmonic map, are studied. These involve the characteristic vector field ξ, and the
almost complex structure in the contact subbundle. Several examples are given where the harmonic section equations for σ reduce
to those for ξ, regarded as a section of the unit tangent bundle. These include trans-Sasakian structures. On the other hand,
there are examples where ξ is harmonic but σ is not a harmonic section. Many examples arise by considering hypersurfaces of
almost Hermitian manifolds, with the induced almost contact structure, and comparing the harmonic section equations for both
structures.
相似文献
993.
In this paper, we investigate the isolated closed orbits of two types of cubic vector fields in R3 by using the idea of central projection transformation, which sets up a bridge connecting the vector field X(x) in R3 with the planar vector fields. We have proved that the cubic vector field in R3 can have two isolated closed orbits or one closed orbit on the invariant cone. As an application of this result, we have shown that a class of 3-dimensional cubic system has at least 10 isolated closed orbits located on 5 invariant cones, and another type of 3-dimensional cubic system has at least 26 isolated closed orbits located on 13 invariant cones or 26 invariant cones. 相似文献
994.
基于矢量调制法的寻北仪 总被引:5,自引:0,他引:5
基于矢量调制法原理,介绍了一套寻北仪设计方案,并详细叙述了该仪器的物理实现方法和算法原理。对影响其精度的主要因素作了详细分析,仿真计算和实验验证了上述理论分析的合理性,并解算出较高精度的测量结果。 相似文献
995.
Some Remarks on the Minty Vector Variational Inequality 总被引:4,自引:0,他引:4
Yang X. M. Yang X. Q. Teo K. L. 《Journal of Optimization Theory and Applications》2004,121(1):193-201
In this paper, we establish some relations between a Minty vector variational inequality and a vector optimization problem under pseudoconvexity or pseudomonotonicity, respectively. Our results generalize those of Ref. 1. 相似文献
996.
C. Singh 《Journal of Optimization Theory and Applications》1988,57(2):369-369
A theorem stated in Ref. 1 is corrected. 相似文献
997.
Path integral expressions are given for the wave function and for the density matrix in a theory which describes state vector reduction. The magnitude of the contribution of each classical path to the propagator is not unity, as in ordinary quantum theory, but depends upon the path. 相似文献
998.
偶碳交替烃也可能存在非键分子轨道,非键轨道的数目由不能作完美匹配的π电子数决定.非键轨道中原子轨道的系数,仍可按零和规则确定,但应设定两个或两个以上的代数值,并满足一个代数关系式. 相似文献
999.
The paper is devoted to studying the lower semicontinuity of vector-valued mappings. The main object under consideration is
the lower limit. We first introduce a new definition of an adequate concept of lower and upper level sets and establish some
of their topological and geometrical properties. A characterization of semicontinuity for vector-valued mappings is thereafter
presented. Then, we define a concept of vector lower limit, proving its lower semicontinuity, and furnishing in this way a
concept of lower semicontinuous regularization for mappings taking their values in a complete lattice. The results obtained
in the present work subsume the standard ones when the target space is finite dimensional. In particular, we recapture the
scalar case with a new flexible proof. In addition, extensions of usual operations of lower and upper limits for vector-valued
mappings are explored. The main result is finally applied to obtain a continuous D.C. decomposition of continuous D.C. mappings.
Dedicated to Alex Rubinov in honor of his 65th birthday 相似文献
1000.
Nitin Nitsure 《Proceedings Mathematical Sciences》1986,95(1):61-77
The purpose of this paper is to compute the Betti numbers of the moduli space ofparabolic vector bundles on a curve (see Seshadri [7], [8] and Mehta & Seshadri [4]), in the case where every semi-stable parabolic bundle is necessarily
stable. We do this by generalizing the method of Atiyah and Bott [1] in the case of moduli of ordinary vector bundles. Recall
that (see Seshadri [7]) the underlying topological space of the moduli of parabolic vector bundles is the space of equivalence
classes of certain unitary representations of a discrete subgroup Γ which is a lattice in PSL (2,R). (The lattice Γ need not necessarily be co-compact).
While the structure of the proof is essentially the same as that of Atiyah and Bott, there are some difficulties of a technical
nature in the parabolic case. For instance the Harder-Narasimhan stratification has to be further refined in order to get
the connected strata. These connected strata turn out to have different codimensions even when they are part of the same Harder-Narasimhan
strata.
If in addition to ‘stable = semistable’ the rank and degree are coprime, then the moduli space turns out to be torsion-free
in its cohomology.
The arrangement of the paper is as follows. In § 1 we prove the necessary basic results about algebraic families of parabolic
bundles. These are generalizations of the corresponding results proved by Shatz [9]. Following this, in § 2 we generalize
the analytical part of the argument of Atiyah and Bott (§ 14 of [1]). Finally in § 3 we show how to obtain an inductive formula
for the Betti numbers of the moduli space. We illustrate our method by computing explicitly the Betti numbers in the special
case of rank = 2, and one parabolic point. 相似文献